Chest CT findings in community-acquired pneumonia due to Coxiella burnetii (Q fever) compared to Streptococcus pneumoniae, a cross sectional study in French Guiana, 2013-2017.

OBJECTIVES: Few and small studies previously examined chest CT-scan characteristics of Coxiella burnetii (Cb) community-acquired pneumonia (CAP). Larger studies are needed to guide physicians towards diagnosis of Q fever in case of pneumonia. METHODS: We conducted a single-center retrospective observational study between 2013 and 2017. All patients with Cb or Streptococcus pneumoniae (Sp) CAP who had a chest CT-scan on admission at Cayenne Hospital (French Guiana) were included. Chest CT-scan were all analyzed by the same expert radiologist. RESULTS: We included 75 patients with Cb CAP and 36 with Sp CAP. Fifty-nine percent of all patients were men (n = 66) and median age was 52 [IQR = 38-62]. Chest CT-scans of Cb CAP patients revealed 67 alveolar condensations (89 %), 52 ground-glass opacities (69 %), 30 cases of lymphadenopathy(ies) (40 %) and 25 pleural effusions (33 %). Parenchyma lesions caused by Cb were predominantly unilateral (67 %). We found high numbers of alveolar condensations in both Cb and Sp CAP (89 % and 75 %; respectively), but the presence of ground-glass opacities was significantly associated with Cb CAP (69 % versus 30 %; p < 0.01). Cb CAP were associated with more lymphadenopathies (40 % vs 17 %; p = 0.01) while Sp CAP showed more bronchial thickening (19 % versus 3 %; p < 0.01) and (micro)nodule(s) ≤1 cm (25 % vs 3 %, p < 0.01). CONCLUSIONS: This large study shows that the most typical aspect of chest CT-scan in case of Cb CAP in French Guiana is a unilateral alveolar consolidation associated with ground glass opacities and lymphadenopathies. C. burnetti and S. pneumoniae both most often cause alveolar consolidations, but present some significantly different CT-scan patterns. This could help physicians through therapeutic choices.

No Signs of Neuroinflammation in Women With Chronic Fatigue Syndrome or Q Fever Fatigue Syndrome Using the TSPO Ligand [11C]-PK11195.

BACKGROUND AND OBJECTIVES: The pathophysiology of chronic fatigue syndrome (CFS) and Q fever fatigue syndrome (QFS) remains elusive. Recent data suggest a role for neuroinflammation as defined by increased expression of translocator protein (TSPO). In the present study, we investigated whether there are signs of neuroinflammation in female patients with CFS and QFS compared with healthy women, using PET with the TSPO ligand 11C-(R)-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline-carbox-amide ([11C]-PK11195). METHODS: The study population consisted of patients with CFS (n = 9), patients with QFS (n = 10), and healthy subjects (HSs) (n = 9). All subjects were women, matched for age (±5 years) and neighborhood, aged between 18 and 59 years, who did not use any medication other than paracetamol or oral contraceptives, and were not vaccinated in the last 6 months. None of the subjects reported substance abuse in the past 3 months or reported signs of underlying psychiatric disease on the Mini-International Neuropsychiatric Interview. All subjects underwent a [11C]-PK11195 PET scan, and the [11C]-PK11195 binding potential (BPND) was calculated. RESULTS: No statistically significant differences in BPND were found for patients with CFS or patients with QFS compared with HSs. BPND of [11C]-PK11195 correlated with symptom severity scores in patients with QFS, but a negative correlation was found in patients with CFS. DISCUSSION: In contrast to what was previously reported for CFS, we found no significant difference in BPND of [11C]-PK11195 when comparing patients with CFS or QFS with healthy neighborhood controls. In this small series, we were unable to find signs of neuroinflammation in patients with CFS and QFS. TRIAL REGISTRATION INFORMATION: EudraCT number 2014-004448-37.

Challenging case of chronic Q fever endocarditis: usefulness of 18F-FDG PET/CT in the diagnosis and follow-up.

Diagnosis of infective endocarditis can be challenging for clinicians, especially when involving prosthetic valves. Recent data suggest that 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) could be a useful diagnostic tool in this setting. Here, we report a case of a patient with an aortic biological prosthesis who presented with a history of fever and fatigue. Echocardiograms were negative for vegetations. The 18F-FDG PET/CT revealed an infective process of the valve and serological tests were positive for chronic Coxiella burnetii infection. Specific treatment for chronic Q fever endocarditis was, therefore, started and the response was monitored using 18F-FDG PET/CT. This case highlights the challenges and pitfalls clinicians face when confronted with prosthetic valve endocarditis and the use of 18F-FDG PET/CT for diagnosis and follow-up.

Utility of positron emission tomography imaging in the diagnosis of chronic Q fever: A Systematic Review.

Chronic Q fever is a diagnostic challenge. Diagnosis relies on serology and/or the detection of DNA from blood or tissue samples. PET-CT identifies tissues with increased glucose metabolism, thus identifying foci of inflammation. Our aim was to review the existing literature on the use of PET-CT to help diagnose chronic Q fever. A literature search was conducted in PubMed and Google Scholar to ascertain publications that included the terms 'Positron Emission Tomography' and 'PET CT' in combination with subheadings 'chronic Q fever' and 'Coxiella burnetii' within the search. To broaden our search retrieval, we used the terms 'chronic Q fever' and 'PET-CT'. Published literature up to 16th April 2020 was included. 274 articles were initially identified. Post-exclusion criteria, 46 articles were included. Amongst case reports and series, the most frequent focus of infection was vascular, followed by musculoskeletal then cardiac. 79.5% of patients had a focus detected with 55.3% of these having proven infected prosthetic devices. Amongst the retrospective and prospective studies, a total of 394 positive sites of foci were identified with 186 negative cases. Some had follow-up scans (53), with 75.5% showing improvement or resolution. Average timeframe for documented radiological resolution post-initiating treatment was 8.86 months. PET-CT is a useful tool in the management of chronic Q fever. Knowledge of a precise focus enables for directed surgical management helping reduce microbial burden, preventing future complications. Radiological resolution of infection can give clinicians reassurance on whether antimicrobial therapy can be ceased earlier, potentially limiting side effects.

Case Report: Visceral Leishmaniasis Falsely Diagnosed as Q Fever.

Visceral leishmaniasis (VL) is a systemic infection caused by the protozoal parasite Leishmania, spread via the bloodstream to the reticuloendothelial system, through the bite of the sand fly. It is endemic in parts of Africa, South America, Asia, and Europe, including the Mediterranean. Here, we describe a case of VL that was initially diagnosed as Q fever based on positive Coxiella burnetii serology and showed a partial response to doxycycline treatment.

Persistent Coxiella burnetii cardiovascular infection on Bentall-De Bono prosthesis.

Coxiella burnetii cardiovascular prosthetic infections are associated with high morbidity and mortality and represent a major health problem due to the lack of standardized management. We were confronted with a C. burnetii infection on Bentall-De Bono prosthesis characterized by a history of vascular infection with relapse that prompted us to screen for cases of C. burnetii on Bentall-De Bono vascular prosthesis monitored in our center. We screened patients between 1991 and 2019, from the French national reference center for Q fever. A microbiological criterion in addition to a lesional criterion was necessary to diagnose C. burnetii persistent vascular infection. Two thousand five hundred and eighty two patient were diagnosed with Coxiella burnetii infection and 160 patients with persistent C. burnetii vascular infection prosthesis, 95 of whom had a vascular prosthesis, including 12 with Bentall-De Bono prosthesis. Among patients with persistent C. burnetii prosthetic vascular infection, patients with Bentall-De Bono prostheses were significantly more prone to develop complications such as aneurysm, fistula, and abscess (62 versus 32%, two-sided Chi-square test, p = 0.04). All but one patient were treated with doxycycline and hydroxychloroquine for a mean (± standard deviation) period of 29.4 ± 13.6 months. Among the 12 patients, 5 had cardio-vascular complications, and 5 had prolonged antibiotherapy with doxycycline and hydroxychloroquine. Patients with C. burnetii vascular infection on Bentall-De Bono tend to be at high risk of developing complications (fistula, aneurysm, abscess, death). Surgery is rarely performed. Clinical, serological, and PET scanner imaging follow-up is recommended.

Q fever endocarditis: is it always subacute or chronic?

Q fever is a zoonotic disease caused by Coxiella burnetii, an obligate intracellular bacterium, which cannot be grown using routine blood culture methods. Although C. burnetii is reported to be the causative agent in approximately 50% of blood culture-negative infective endocarditis cases in developed countries, the incidence in Turkey is yet to be defined. The clinical course of Q fever endocarditis is generally subacute and chronic; the disease may be present for years with only subtle symptoms and no vegetation visible on echocardiography while the bacteria gradually destroy the heart valves. This is the case of the successful treatment of a young man with Q fever endocarditis that had an acute clinical course. In 1 month, he developed New York Heart Association class IV heart failure and a large, 3-cm vegetation was observed on an echocardiogram.

Acute Q fever pneumonia: high-resolution computed tomographic findings in six patients.

METHODS:: We analyzed high-resolution CT (HRCT) findings from six male patients (mean age, 22.6 years) with confirmed diagnoses of acute Q fever. Two chest radiologists analyzed the images and reached decisions by consensus. All patients presented fever, myalgia, prostation, headache, and dry cough. They also had common epidemiologic factors (recent travel for military service, where they had contact with sheep and capybara). Diagnoses were confirmed by the detection of C. burnetii DNA in clinical samples by polymerase chain reaction. RESULTS:: The predominant HRCT findings were areas of consolidation (100%) and nodules (66.6%) with halos of ground-glass opacity, predominantly with segmental and peripheral distributions. Lesions affected all lobes, and predominated in the left upper and lower lobes. Involvement of more than one lobe was observed in four patients. No pleural effusion or lymph node enlargement was found. CONCLUSION:: The predominant HRCT findings in patients with acute Q fever pneumonia were bilateral, peripheral areas of consolidation and nodules with irregular contours and halos of ground-glass opacity. ADVANCES IN KNOWLEDGE:: Acute Q fever should be included in the differential diagnosis of lesions with the halo sign on HRCT.

A case of giant cell arteritis associated with culture-proven Coxiella burnetii aortitis.

A case of proven Coxiella burnetii aortitis, possibly associated with giant cell arteritis (GCA), is reported. A 72-year-old man, who is a hunter, presented with weight loss, fever, jaw claudication, and hardened temporal arteries associated with a persistent inflammatory syndrome and arteritis of the whole aorta, including the brachiocephalic arteries, as seen on 18F-fluorodeoxyglucose positron emission tomography/computed tomography. The diagnosis of GCA was retained, and treatment with prednisolone was started. Given the aneurysm of the abdominal aorta, the patient underwent replacement of the abdominal aorta with an allograft. Histology showed intense chronic arteritis attributed to atherosclerosis with dissection. However, Coxiella burnetii infection was confirmed by serology and then by culture and molecular biology on the surgical specimen. A combination of hydroxychloroquine and doxycycline was added to tapered prednisolone and the outcome was favourable.

The Value of 18F-FDG PET/CT in Diagnosis and During Follow-up in 273 Patients with Chronic Q Fever.

In 1%-5% of all acute Q fever infections, chronic Q fever develops, mostly manifesting as endocarditis, infected aneurysms, or infected vascular prostheses. In this study, we investigated the diagnostic value of 18F-FDG PET/CT in chronic Q fever at diagnosis and during follow-up. Methods: All adult Dutch patients suspected of chronic Q fever who were diagnosed since 2007 were retrospectively included until March 2015, when at least one 18F-FDG PET/CT scan was obtained. Clinical data and results from 18F-FDG PET/CT at diagnosis and during follow-up were collected. 18F-FDG PET/CT scans were prospectively reevaluated by 3 nuclear medicine physicians using a structured scoring system. Results: In total, 273 patients with possible, probable, or proven chronic Q fever were included. Of all 18F-FDG PET/CT scans performed at diagnosis, 13.5% led to a change in diagnosis. Q fever-related mortality rate in patients with and without vascular infection based on 18F-FDG PET/CT was 23.8% and 2.1%, respectively (P = 0.001). When 18F-FDG PET/CT was added as a major criterion to the modified Duke criteria, 17 patients (1.9-fold increase) had definite endocarditis. At diagnosis, 19.6% of 18F-FDG PET/CT scans led to treatment modification. During follow-up, 57.3% of 18F-FDG PET/CT scans resulted in treatment modification. Conclusion:18F-FDG PET/CT is a valuable technique in diagnosis of chronic Q fever and during follow-up, often leading to a change in diagnosis or treatment modification and providing important prognostic information on patient survival.

18F-FDG PET/CT as a central tool in the shift from chronic Q fever to Coxiella burnetii persistent focalized infection: A consecutive case series.

Because Q fever is mostly diagnosed serologically, localizing a persistent focus of Coxiella burnetii infection can be challenging. F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) could be an interesting tool in this context.We performed a retrospective study on patients diagnosed with C burnetii infection, who had undergone F-FDG PET/CT between 2009 and 2015. When positive F-FDG PET/CT results were obtained, we tried to determine if it changed the previous diagnosis by discovering or confirming a suspected focus of C burnetii infection.One hundred sixty-seven patients benefited from F-FDG PET/CT. The most frequent clinical subgroup before F-FDG PET/CT was patients with no identified focus of infection, despite high IgG1 serological titers (34%). For 59% (n = 99) of patients, a hypermetabolic focus was identified. For 62 patients (62.6%), the positive F-FDG PET/CT allowed the diagnosis to be changed. For 24 of them, (38.7%), a previously unsuspected focus of infection was discovered. Forty-two (42%) positive patients had more than 1 hypermetabolic focus. We observed 21 valvular foci, 34 vascular foci, and a high proportion of osteoarticular localizations (n = 21). We also observed lymphadenitis (n = 27), bone marrow hypermetabolism (n = 11), and 9 pulmonary localizations.We confirmed thatF-FDG PET/CT is a central tool in the diagnosis of C burnetii focalized persistent infection. We proposed new diagnostic scores for 2 main clinical entities identified using F-FDG PET/CT: osteoarticular persistent infections and lymphadenitis.

Value of 18F-FDG PET/CT in diagnosing chronic Q fever in patients with central vascular disease.

BACKGROUND: The aim of this study is to describe the value of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in diagnosing chronic Q fever in patients with central vascular disease and the added value of 18F-FDG PET/CT in the diagnostic combination strategy as described in the Dutch consensus guideline for diagnosing chronic Q fever. METHODS: 18F-FDG PET/CT was performed in patients with an abdominal aortic aneurysm or aorto-iliac reconstruction and chronic Q fever, diagnosed by serology and positive PCR for Coxiella burnetii DNA in blood and/or tissue (PCR-positive study group). Patients with an abdominal aortic aneurysm or aorto-iliac reconstruction without clinical and serological findings indicating Q fever infection served as a control group. Patients with a serological profile of chronic Q fever and a negative PCR in blood were included in additional analyses (PCR-negative study group). RESULTS: Thirteen patients were evaluated in the PCR-positive study group and 22 patients in the control group. 18F-FDG PET/CT indicated vascular infection in 6/13 patients in the PCR-positive study group and 2/22 patients in the control group. 18F-FDG PET/CT demonstrated a sensitivity of 46% (95% CI: 23-71%), specificity of 91% (95% CI: 71-99%), positive predictive value of 75% (95% CI:41-93%) and negative predictive value of 74% (95% CI: 55-87%). In the PCR-negative study group, 18F-FDG PET/CT was positive in 10/20 patients (50%). CONCLUSION: The combination of 18F-FDG PET/CT, as an imaging tool for identifying a focus of infection, and Q fever serology is a valid diagnostic strategy for diagnosing chronic Q fever in patients with central vascular disease.

Sternoclavicular joint infection caused by Coxiella burnetii: a case report.

BACKGROUND: Few cases of Q fever osteoarticular infection have been reported, with chronic osteomyelitis as the most common manifestation of Q fever osteoarticular infection. Here we present the case of a sternoclavicular joint infection caused by Coxiella burnetii and localized by positron emission tomography scanning. CASE PRESENTATION: A 67-year-old French man from south France was hospitalized for fever and confusion. An examination revealed subclavicular and axillary lymph node enlargement. Computed tomography scanning and transesophageal echocardiogram were normal, and magnetic resonance imaging scanning did not reveal signs of infection. An immunofluorescence assay of an acute serum sample was positive for C. burnetii and he was treated with 200 mg doxycycline for 21 days. An immunofluorescence assay of convalescent serum sampled after 2 months revealed very high C. burnetii antibody titers. To localize the site of the infection, we performed positron emission tomography scanning, which revealed intense fluorodeoxyglucose uptake in his right sternoclavicular joint; treatment with 200 mg oral doxycycline daily and 200 mg oral hydroxychloroquine three times daily for 18 months was initiated. CONCLUSIONS: Q fever articular infections may be undiagnosed, and we strongly urge the use of positron emission tomography scanning in patients with high C. burnetii antibody titers to localize the site of C. burnetii infection.

Treatment of an Abdominal Aortic Aneurysm Infected by Coxiella Burnetii Using a Cryopreserved Allograft.

Q fever is a worldwide zoonosis caused by an intracellular bacillus named Coxiella burnetii (CB) and is a rare cause of vascular infections. We report a case of abdominal aortic aneurysm infected by CB with bilateral paravertebral abscesses and contiguous spondylodiscitis treated by open repair using a cryopreserved allograft and long-term antibiotic therapy by oral doxycycline and oral hydroxychloroquine for a duration of 18 months. Twenty months after the operation, the patient had no infections signs and vascular complication.

18-FDG PET/ CT Scan in the Diagnosis and Follow-up of Chronic Q fever Aortic Valve Endocarditis.

Chronic Q fever endocarditis is a rare but important infection associated with risk of morbidity and mortality. Echocardiography rarely visualises the vegetative lesion. We describe the first Australian report of chronic Q fever aortic valve endocarditis confirmed with the use of 18 -FDG PET/ CT scan. Following valvular replacement, the patient had ongoing high serological titres despite active treatment and he was managed with yearly serial PET/ CT scan to confirm the absence of active infection. The utility of serial PET /CT scan imaging as a follow-up management strategy has not been described in the literature previously and should be investigated further.

A Case of Silent Q Fever Endocarditis.

Q fever endocarditis is a rare, culture negative endocarditis caused by Coxiella burnetii, a spore-forming gram negative coccobacillus. Presenting symptoms can be very non-specific; thus, diagnosis may be delayed. We present a case of a 65-year-old male patient with history of aortic aneurysm who complained of chronic fatigue. He was found to have aortic valve vegetation on routine echocardiography. Q fever endocarditis was diagnosed based on elevated Q fever serology; there was absence of fever. This case illustrated a rare, under-recognized and atypical manifestation of Q fever endocarditis. We would like to encourage physicians of rural states like South Dakota to remain vigilant when it comes to screening for the suspected cases of Q fever, specifically in cases of unexplained fatigue and valvulopathy.